In the field of the diagnosis of various ailments of the esophageal region of the body, such as achalasia, scleroderma, spasm, hiatal hernia, etc., the measurement of the pressure in the esophagus can be very helpful.
Insertion of a catheter having a piezoelectric transducer mounted thereon to measure pressures in internal body cavities such as the esophagus is known in the presently existing art. One such of a flexible tube has at least one piezoelectric transducer mounted on the outer surface of the flexible tube. The transducer arrangement on the catheter is for a transducer which is only sensitive to an area on the surface of the flexible tube which corresponds to less than one-half the circumference of the flexible tube. Furthermore, the configuration of the apparatus is of a transducer diaphragm, which is mounted on the external portion of the flexible tube and, therefore, is susceptible to certain inaccuracies created when only a portion of the transducer diaphragm is in contact with the surface of the internal body cavity into which the flexible tube catheter is inserted.
It would, therefore, be desirable to have a transducer which is insertable on a catheter, which transducer is sensitive to pressure variations about the entire circumference of the catheter. In addition, it would be desirable to have a housing for the transducer such that the diaphragm of the transducer does not itself contact the walls of the internal body cavity into which the catheter is inserted.